Field of the Invention
The present invention relates to an apparatus for collecting a lighter fraction floatable liquid from a heavier fraction liquid, such as a lighter fraction floating oil from a heavier fraction water. The invention also relates to a method for collecting a lighter fraction floatable liquid from a heavier fraction liquid making use of such an apparatus.
Description of Related Art
Removal of a layer of pollutant floating on a liquid is an actual problem that has worldwide attention. Reference is made to several more or less accidents that took place during recent years as a result of, for instance, oil and gas recovery, transportation of oil and other fluid products, and storage of polluting liquids. The most striking example is the disaster that started in April 2010 in the Gulf of Mexico as a result of a malfunctioning blowout preventer system. Millions of liters of oil were spilled and only a few percent of the spilled oil was recovered. Vessels with cleaning arms where not able to collect a serious amount of the spilled oil so the decision was made to use chemicals for dissolving the oil in the seawater. This was not only bad for environmental reasons it is also economically undesired.
In the prior art also a mechanical type of oil extraction station is known from U.S. Pat. No. 5,713,697 that provides a vat-like collecting container to be immersed into water that is partly borne on an annular float. Below the float and connected to the collecting container is a parabolic intake trough that leaves in between the float and the intake trough an inlet opening for the oil and gasoline floating on the water. The dimension S of the inlet opening between the float and the intake trough is variable by relative movement of the float and the intake trough. The type of apparatus as disclosed in this patent provides not the required functionality of effective oil extraction in variable circumstances and is not the answer to effective cleaning of oil spillage in practise.
The intention of the present invention is to provide more effective and efficient equipment and working methods than the prior art provides for collecting a lighter fraction floatable liquid from a heavier fraction liquid under variable circumstances, such as a lighter fraction floating oil from a heavier fraction water.